302 NEW ZEALAND NATURE-STUDY BOOK 
Refer again to the localities where Gravel and Shingle 
are being formed. Are these likely to be found far from 
the sea-shore Why not? A strong current is required to 
force them along. The rivers sweeping down into the 
sea cannot carry them far, for the current is checked on 
reaching the sea. The currents along the coasts, too, are 
unable to move them to any great distance. Educe then 
that Conglomerate has been formed in a river-bed or along 
a coast line, not far from land. Contrast with what has 
already been learnt about the origin of Sandstone and 
Shale. 
Note.—When the fragments are angular, the rock is called 
a breccia. 
Notre.—There will be little or no difficulty in enabling pupils to 
recognise the characteristics of some of the commoner of the sedi- 
mentary rocks, ¢.g., their stratification and fragmental origin. 
Stratification to be‘realised should be seen in the field, so that it 
will be necessary to direct the attention of pupils to some typical 
exposures in the district if time cannot be found for taking the 
whole class to examine these in situ. The latter, of course, is the 
more preferable plan, and should be adopted when possible. 
The two kinds of rock, aqueous and igneous, should be care- 
fully contrasted and their differences noted—igneous, massive, and 
crystalline ; aqueous, fragmentary, and non-crystalline. 
Some time should be devoted to determining the aqueous origin 
of certain rocks. If fossil-bearing strata occur in the neighbourhood, 
a visit to these should certainly be made—not with the object of 
collecting fossils, though such work has its use—but for the 
purpose of bringing children into contact with perhaps the most 
convincing proof of the conditions under which the rocks were 
formed. ‘To those who have already been through a course of 
lessons on molluscs, and have begun to identify forms by their 
shape, appearance, and markings, a fossil bed will prove of great 
interest, especially if it be of recent age. Under certain con- 
ditions pupils might be encouraged to collect and, aided by the 
teacher, to identify, care being taken to note the kind of rock in 
which the fossils occur. <A collection thus obtained would be 
of great use in any school and would serve to bring home to 
children as perhaps nothing else would that much of the solid crust 
